Grinding wheel



A. P. BEEBE GRINDING WHEEL Filed Jan 26, 1954 INVENTOR. fllafl P Beebe.

ATTORNEYS Patented Dec. 11, 1934 UNITE GRINDING WHEEL Alan P. Beebe, Detroit, Mich.,

assignor to Peninsular Grinding Wheel Company, a corporation of Michigan Application January 26 9 Claims.

This invention relates to grinding wheels and more especially to the construction of and method of making grinding wheels of the metal backed type.

The objects of the present invention are to provide a readily detachable grinding wheel including a metal backing disc of rigid construction and firmly bonded to a disc of abradant material; to increase the effective area of contact between the metal backing disc or parts fixed thereto and the abrasive material while at the same time providing a grinding wheel that may be worn down to a small fraction of aninch in thickness without materially reducing the strength and rigidity of the wheel; to provide a grinding wheel backing disc adapted to be bonded to a preformed disc of abradant material; to provide a metal backing disc of the above character so economical of construction that it may be thrown away when the grinding wheel is worn down; to provide metal backing and abradant discs of such construction that parts of the grinding wheel hold together even though the abradant material breaks in use; and to provide a backing disc of the above character which will not injure work operated upon in the event that the abradant material is worn down until parts of the backing disc are exposed.

Other objects, features and advantages will become apparent from the following description and appended claims.

For the purpose of illustrating the genus of the invention, a typical concrete embodiment thereof is shown in the accompanying drawing, wherein:

Figure 1 is a front face elevation of a grinding wheel constructed according to this invention, the grinding disc being broken away to show the form of the backing disc employed;

Fig. 2 is a central section taken on the line 2-2 of Fig. 1;

Fig. 3 is an enlarged fragmentary section taken on the line 3-3 of Fig. 1; and

Fig. 4 is a view similar to Fig. 3 of a modified form of grinding disc which may be employed.

Referring to the drawing, the numeral designates a grinding wheel comprising a disc 11 of abradant material and a binder and a backing disc 12, preferably constructed of thin sheet metal. The wheel 10 is adapted to be fixed to a rotatable support 14; operable by a drive shaft 15.

The backing member 12 is preferably constructed of thin sheet steel and in the form of a centrally apertured annular disc provided with outwardly turned flanges 15 and 16 at the inner and outer peripheries thereof. The forward face of the backing member 12 is provided with a 1934, Serial No. 708,343

plurality of concentrically arranged annular strip members 20. These strip members are preferably welded to the forward face of the backing member 12 as indicated at 17. The backing member 12 is provided with a plurality of apertures 18 through which securing elements may be passed for detachably fixing the grinding wheel 10 to the rotatable support 14.

In the construction of the grinding wheel 10 an annular disc is spun or stamped to provide the flanges 15 and 16 and metal strips 20 are bent to annular form and clamped to the forward face of the backing member 12 so that the rearwardly disposed edge portions thereof may be welded at spaced points to the forward face of the backing member 12. The strips 20 are preferably provided with rounded edge portions'as. indicated at 21 in Figs. 2 and 3. The apertures 18 are then drilled adjacent but slightly spaced from certain of strip members 20 so that flat faces of non-circular portions of certain securing elements may be abutted against the strip members to prevent rotation of these securing elements relative to the backing member 12.

The concentric arrangement of the annular strip members 20 makes it easy to jig drill the apertures 18. Securing elements such as bolts 22 are then inserted in the apertures 18 and the abradant disc 11 is molded, or otherwise formed, on the forward face of the backing member 12 so as to embed the strips 20 and non-circular portions of the securing elements, such as 22, therein. By providing rounded edge portions of the annular strips 20, the abradant material and binder therefor will be dovetailed -under the rounded edge portions 21 to more securely bond the abradant disc to the backing member. In the event that the binder for the particles of abraded material will not form a secure bond to the sheet metal backing member 12, the latter may be faced with a suitable cement or other bonding agent which will adhere both to the particles of abradant material and to the metal disc. The rounding of the forward edge portions of the strips 20 provides but a small surface which could contact with the work if the disc of abradant material is worn down to the backing member or parts fixed thereto.

The flanges 15 and 16 and the annular strip members 20 provide extensive laterally disposed holding surfaces to which the abradant material may be bonded. The flanges 15 and 16 and strip members 20 also strengthen and stiffen the backing member 12 and aid in preventing breakage of the abradant disc as it is subjected to centrifugal forces when the grinding wheel is rotated at high speeds. Nuts 23 may be provided for cooperating with the bolts 22 in securing the grinding wheel to the rotatable support 14. It is obvious that the securing elements 22 and 23 may be reversed with the nuts 23 embedded in the abradant disc 11 and abutting the forward face of the backing member 12 and certain of the annular strip mem bers 20 to prevent undesired rotation thereof. The illustrated arrangement, however, is preferred since the heads of the bolts 22 may be made slightly less in thickness than the depth of the strip members 20 and flanges 15 and 16 so that the concentric edge portions of the flanges and strip members will be the only elements which would be exposed to the work in the event that the grinding disc is worn down to expose parts of the backing member. .Other arrangements of the openings 18 may be made so that the grinding wheel may be readily attached to rotatable supports 14 having different bolt hole patterns. Where necessary, certain of the strips 20 may be changed in shape, size or position to accommodate such openings. It is also noted that therstrips 20 'may be arranged in other than concentric relation and may be of other than annular form if desired. It is also noted that the nut and bolt elements 22 and 23 may be provided with crimped or otherwise deformed portions embedded in the grinding disc instead of the non-circular portions shown.

Referring more particularly to Fig. 4 of the drawing, a construction of grinding wheel is disclosed in which a bonding material, such as magnesium oxychloride, which will attack or corrode metal so as to loosen the bond between the abradant material and the backing member 12, may be employed. This construction could also be employed in the construction of grinding wheels in which such high temperatures are required for fusing the bonding material that the backing member 12 would become distorted or warped during the molding operation of the grinding disc. In this construction the grinding disc 11 is preformed and provided with a plurality of annular and concentrically arranged grooves 24 on the rear face thereof. The construction of the backing member 12 is the same as that previously described. The grooves 24 may be filled with a cement 25 or other suitable bonding material, resistant to the corrosive action of magnesium oxychloride in the event that the latter is employed as the bonding agent for the abradant material, and the abradant disc and backing member assembled by pressing the flanges 15 and 16 and annular strip members 20 into the bonding agent 25.

As many changes could be made in the above constructions and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A grinding wheel comprising a backing member including a disc of thin sheet metal and a plurality of annular members of thin strip metal each secured at an edge thereof to said disc and embedded in a disc of abradant material.

2. A grinding wheel comprising a backing member including a disc of thin sheet metal and a plurality of annular members in the form of thin strip metal, each welded at spaced points to said disc and embedded in a disc of abradant material.

3. A grinding wheel comprising a disc of abradantmaterial and a backing member therefor including a sheet metal disc provided with an upturned flange countersunk in the outer periphery of said abradant? disc and a plurality of strip metal elements bent to annular form, secured in concentric relation at edge portions thereof to said metal disc, and embedded in said abradant disc.

4. A grinding wheel comprising a centrally fapertur ed disc of abradant material and a backing member therefor comprising a centrally apertured sheet metal disc provided with upturnedflanges at the inner and outer peripheries thereof and countersunk in the inner and outer peripheries of said abradant disc, and a plurality of strip metal elements, each bent to annular form, secured in concentric relation at edge portions thereof to said metal disc, and embedded in said abradant disc.

5. A grinding wheel comprising a disc of abradant material provided with a plurality. of concentric annular grooves in one face thereof, a backing member for said abradant disc including a sheet metal disc and a plurality of concentrically arranged annular strip metal members welded at edge portions thereof to said metal disc and adapted to be received in the grooves in said abradant disc, and means in said grooves for bonding said backing member to said abradant disc.

6. A grinding wheel comprising a disc of abradant material, a backing member including a disc of thin sheet metal, a plurality of annular members in the form of thin strip metal, each strip member being welded along an edge portion thereof to said metal disc and embedded in said disc of abradant material with the side faces of the strip members arranged at substantially right angles to the plane of said metal disc, and A;

securing elements for attaching said wheel to a rotatable support, certain of said securing el ments being provided with non-circular portions embedded in said abradant disc and adapted to abut certain of said strip members to prevent rotation thereof relative to said metal disc.

'7. The method of making a grinding wheel which comprises, forming an annular disc of sheet metal, bending a plurality of metal strips of different lengths to annular form, clamping said annular strips in concentric relation on one face of said metal disc, and welding edge portions of said annular strips to said disc, and then forming a disc of abradant material on one face of said metal disc and about said annular strip members.

8. The method of making a grinding wheel which consists in forming a disc of abradant material, forming a plurality of concentric annular grooves in one face of said abradant disc, forming a sheet metal disc, welding a plurality of annular strip members to said metal disc in position to be received in said grooves, disposing a bonding agent in said grooves and then pressing said metal disc against said abradant disc wi h said annular strip members disposed in said grooves.

9. As an article of manufacture, a backing member for a grinding wheel comprising an annular disc of sheet metal and a plurality of metal strips welded at edge portions thereof to one face of said metal disc.

ALAN P. BEEBE. 

